Another inborn error of immunity, CGD, is caused by mutations in genes encoding components of the reduced nicotinamide dinucleotide phosphate (NADPH) oxidase complex: gp91phox, p22phox, p67phox, p40phox, or p47phox, which generates reactive oxygen species (ROS) [28, 29]. The gene discussed is CYBB; the disease is chronic granulomatous disease.